From the Workbench
Hardware tinkering, test equipment repairs, and builds that involve soldering irons, oscilloscopes, and occasionally voiding warranties.
Fixing a Rohde & Schwarz CMU200/300
A CMU200 Universal Radio Communication Tester picked up from eBay in non-working condition. These units were originally $40,000+ instruments used for testing cellular handsets, base stations, and RF components. This project covers the full journey: initial diagnosis, identifying failed components at the board level, sourcing replacements, repair, and getting the unit back to calibration. The CMU200 supports GSM, WCDMA, CDMA2000, and general-purpose RF measurement — making it a powerful tool for ham radio experimentation once restored.
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Repurposing an Anritsu MD8475A
The MD8475A started life as a six-figure cellular signaling tester. What it also has is a rugged industrial chassis, a gorgeous 12.1″ LCD display, a Core i7 industrial motherboard, and an integrated GPIB interface — all in a case that looks like it belongs in a serious lab. This project strips out the cellular-specific hardware and turns the chassis into a multi-purpose workbench platform: integrated SDR radio, GPIB control interface for oscilloscopes and other test equipment, and potentially an HF amplifier down the line. The goal is one box that ties together multiple instruments and capabilities.
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ESP32-S3 Remote Control Knob
A custom hardware controller for ham radios built around an ESP32-S3 with a round LCD touchscreen. Connects to the OmniRig Server over WiFi via TCP, with UDP broadcast for automatic discovery. The LVGL-based UI provides a physical tuning knob experience — rotate to change frequency, tap to switch bands or modes. Designed to sit on the desk and give tactile control when the radio is in another room.
Read more →Hermes Lite 2
The Hermes Lite 2 is an open-source, low-cost HF software-defined radio transceiver based on a direct-conversion architecture. It covers 160m through 6m with up to 5W output and uses the OpenHPSDR Ethernet protocol — meaning it works with SDR applications like SparkSDR, Thetis, and PowerSDR. This project covers setup, integration with the shack, and experiments with the platform.
Read more →What’s Next
Current project in the pipeline: a 130ft end-fed half-wave antenna using a tall pine tree and drone-assisted wire deployment. Check the home page for the latest updates.